累积损伤对B炸药冲击起爆影响的仿真研究

Simulation Study on the Effect of Cumulative Damage on the Shock Initiation of Composition B

采用LS-DYNA软件进行数值仿真,通过改变炸药撞击速度以改变损伤程度,探究损伤和垫层材料对B炸药起爆行为的影响。计算结果表明,当第2次撞击速度一定时,起爆时间t与第1次撞击速度v_(1)的关系为:t=-0.02 v_(1)+C_(1),冲击起爆的距离也随之减小。主要因为第1次撞击速度增大,导致B炸药发生轻微变形,内部的损伤程度随之增大,第2次撞击时更容易被起爆。3种不同垫层中,波阻抗较大的材料抗撞击能力强,B炸药内部不易产生损伤,冲击起爆的时间和距离较长;而B炸药的临界起爆压力差别不大,临界起爆压力的范围在31.4832.98 GPa之间。表明不同垫层材料会影响损伤后B炸药冲击起爆的时间和距离,而不会影响临界起爆压力。

In order to study the influence of damage and cushion materials on the initiation of Composition B,numerical simulation was conducted using LS-DYNA software.The impact velocity of explosive was changed to change the damage degree.The calculation results show that when the second impact velocity is fixed,the relationship between the initiation time t and the first impact velocity v_(1) is t=-0.02v_(1)+C_(1),and the distance of impact detonation also decreases accordingly.The increase of the first impact velocity leads to the slight deformation of the explosive,and the damage degree inside the explosive increases.Therefore,the explosive is easier to be triggered during the second impact.Among the three different cushions,the material with higher resistance to impact is stronger.The internal damage of the explosive containing this material is not easy to produce,and the time and distance of impact initiation of this explosive are longer.The critical initiation pressure of the explosive varies little,ranging from 31.48 GPa to 32.98 GPa.It indicates that different cushion materials will affect the time and distance of impact initiation of the damaged explosive,but will not affect the critical initiation pressure.